Bit and tap chuck.



WILLIAM L. rnocumnn, or (intense, ILLIN-OIS.

srr AND TAP encore.

Specification of Letters Patent. o figi s ne atnn a' .flune 1c, '1911, Serial No. 633,531.

Divided andthis application filed November 14, 1913. Serial No. 800,919.

T l i h mif m t/rammffiBeljitf' known" that I, VILLIAM L. Paoot nmm'a 'citi'z of' the United States, residing 'atf Chicago,,1 the county of- Cook and State'oflllinois, reinvented new and usefullmprovemefnt' Bit and Tap Chucks, of

- which. tlie'f ollowirigl is a specification, ref- .erencebeing had to the accompanying draw I -1ngs for ining a part thereof.

Th sin'vention' relates to improvements in the'to'ol holding means of bit and ta chucks designed particularly tap ing machines.

The present a plication is a division of my application er. No. 633,531, filed June 16, 1911, and issued in Patent No. 1,037,796, dated, September 3,1912.

It consists of the features and elements described and shown in the drawings as indicated by the claims. ----In the drawings :Figure 1 is an elevation partly in section showing a chuck embodying this invention with a tap inserted in position for use therein. Fig. 2 is a transverse section taken as indicated at line 22 on Fig. 1. Fig. 3 is a section taken as indicated at line 33 on Fig. l with the cap nut removed.

The drawings illustrate a chuck provided with'the usual tapered shank, A, and with a specially constructed friction drive incloscd in a casing, B, and described in detail in my above mentioned patent.

The present invention relates to means for holding the tool in the lower end of the. chuck,.such means being shown in section in Fig. 1. It is well known that absolute uniformity is not found in respect to the dimensions-of the round shank, 0;, of the drill or tap and the squared upper end, 7 which is positively engaged for driving. The tool'is preferably centered by some engagement of the shank at its round portion. 01, and is preferably driven by a positive engagement with its squared end, y, and it is important, therefore, that any device for engaging the tool should effect such engagement positively and definitely both at the round portion and at the squared portion, and that neither eugagement should forestall or defeat the other. For this purpose I provide -,in the element, 1, a conical downwardly opening cavity, 1 while the element, 1, is exteriorly threaded to receive an interior-1y threaded follower, 2, having in its lower end a eonifor use in dril ing and Patented Nov. 17,1914.

cal upwardly opening cavity, 2?, preferably ofthe same taper as the conical cavity, 1.

In the conical cavity, 1, there are lodged two jaws, 3, 3, exteriorly tapered comically to fit approximately the taper of the conical chamber, 1, and having their meeting faces notched to engage the squared end. 3 of the tool shank of the customary form as illustrated. The two j aws, 3,3, are engaged with the element, 1, for positive rotation thereby by means of the'c'ross pin, 4, which is insorted through the upper, smaller end of the jaws and engages a diametrically positioned longitudinal rift, 1?, in the said eoni-f cal-chamber extending across the lower end of the element 1. In the conical cavity of the follower, 2, there'are lodged two semiconical jaws, 5, 5, notched on their meeting faces for engaging the round portion. a:, of the tool shank. \Vith this construction it will be observed that when the tool is inserted through the lower central aperture, 2", of the follower, E2, and up between the jaws, 5, and then on up between the jaws, 3, 3, the rotation of the follower across it on to the element. 1, will cause the jaws, 5, 5. whose upper faces rest up against the lower faccs of the jaws, 3, 3. to force said jaws, 8, 3, up into their conical seat in the element. 1, until said jaws are closed upon the sq mrod end. of the tool, and that if when this happens the jaws, 5, 5, have not yet closely grasped the round shank, ac, of the tool, the follower. 2, can be still further screwed up until said round portion is thus firmly grasped by the lower jaws. On the other hand. if the jaws. 5, 5, become closed firmly upon the round portion ofthe shank before the jaws, 3. 3. have firmly grasped the squared end, the follower can be screwed up until the latter engagement is perfectly c'l'llected. Whcmrvcr. therefore, the operator finds the fo lower tight. he is thereby assured that the tool is not ouly grasped firmly at its squared end for positive driving, but is also grasped firmly at its round shank for centering. And this result will be obtained regardless of any ordinary variations from the standard in the size of either portion of the tool shank.

1. A chuck comprising a toolholding member having a tapered cavity in one end and a centrally apertured follower, adapted to be screwed onto said end and having its cavity tapered to the central aperture, said two elements having their tapered cavities with said first mentioned element for rota-.

tion therewith.

2. A chuck comprising an element having in one end a tapered cavity widest at the end, and a follower screwed onto ,said end and having a tapered cavity merging at its smaller end in an axial aperture through the end of the cap nut; cooperating tool gripping jaws in each of said cavities, tapered to fit t e respective cavities, those in one cavity meeting those in the other cavity base to base; and means for engaging the jaws in the first mentioned cavity with. the first mentioned element for rotation therewith.

3. A chuck comprising a tool holding ele- 'ment having in one end a tapered cavity and having a longitudinal slot opening into such cavity; a 0 lower screwed onto said elesaid first mentioned element, and a pair of tool gripping jaws lodged in the cavity of the cap and tapered to fit the same, the larger bases of thetwo pairs of tapering jaws resting against each other; whereby the cap or follower being screwed onto the first mentioned clement causes both pairs of jaws to grip an axially positioned tool extended between both pairs.

In testimony whereof I have hereunto set my hand at Chicago, Illinois, this 8th day'of November, 1913.

WILLIAM L. PROCUNIER.

Witnesses:

- Rona". N. BURTON, CHAS. Si Bnirron. 

